Fasting is a process in which you severely restrict eating (and sometimes drinking) for a period of time.

Some fasts last for a day. Others last over a month. The duration of a fast depends on the person and their reasons for fasting.

If you experience diarrhea while fasting, you should end your fast until symptoms improve. Keep reading to learn why.

Diarrhea occurs when the food and nutrients passing through the gastrointestinal (GI) tract move too quickly and exit the body without being absorbed.

Diarrhea during a fast may cause side effects such as:

Diarrhea and side effects like dizziness during a fast can be stressful and dangerous. While fasting, your body is already more likely to be dizzy, tired, and nauseous. These are only made worse with diarrhea.

For some people, the combination of fasting and diarrhea can even lead to passing out.

For these reasons, it’s recommended to end your fast until symptoms improve, and then continue to fast once you’re no longer experiencing diarrhea and its side effects.

Other symptoms that signal you should end your fast

Along with diarrhea, consider ending your fast if you experience:

During a fast, diarrhea may occur because of an oversecretion of water and salts in the GI tract. A number of triggers can cause this, including drinking liquids high in caffeine, such as tea or coffee.

Usually, fasting doesn’t cause diarrhea on its own. In fact, you’re more likely to get diarrhea from breaking your fast than you are while performing the fast. That’s because your bowel’s ability to function properly decreases when it’s not used.

Other common causes of diarrhea include:

Before starting a fast — or if you have health concerns while fasting, including diarrhea — it’s a good idea to see a doctor.

Diarrhea is uncomfortable, but it’s usually not life-threatening. However, if you’re experiencing any of the following symptoms alongside diarrhea, contact your doctor immediately:

Depending on the cause of your diarrhea, the treatment will vary.

Home remedies

You can treat many cases of diarrhea at home with some quick dietary changes:

  • Drink lots of water.
  • Avoid sugary and caffeinated drinks.
  • Drink diluted juice, weak tea, or electrolyte-replacement, drinks like Gatorade or Pedialyte.
  • Increase foods high in soluble fiber.
  • Increase foods high in potassium and salt.


If home remedies aren’t helping, you may get relief from over-the-counter medications, including:

Ending your fast due to diarrhea

When ending your fast because of diarrhea, consider starting with the BRAT diet (banana, rice, applesauce, toast).

This diet features food that’s bland, starchy, and low in fiber. It helps firm stools and replace lost nutrients.

You should also:

  • Eat small meals.
  • Avoid fried food.
  • Avoid foods that cause gas, such as beans and broccoli.

Some people fast for health reasons, while others fast for religious or spiritual reasons.

Advocates of fasting suggest that the practice yields the following benefits:

The Mayo Clinic suggests that regular fasting may decrease LDL (bad) cholesterol levels and may improve the way your body metabolizes sugar.

However, there’s very little scientific evidence about the effects of fasting on the human mind and body.

Since going without food for long periods of time is taxing on the body, it’s important to be aware of any problems that may arise during a fast, such as diarrhea.

Diarrhea is a common GI problem that everyone experiences from time to time. Diarrhea can be particularly debilitating — and dangerous — while fasting.

If you experience diarrhea while fasting, consider breaking your fast. You can always continue your fast once the diarrhea subsides.

If you experience any worrying symptoms, such as dizziness, loss of consciousness, nausea, vomiting, or bloody stools, contact a doctor immediately.